MUDDY CREEK TWP — Traffic on Interstate 79 at the Route 422, Exit 99 Interchange, will be reduced to a single lane in each direction beginning Thursday, the state Department of Transportation announced this morning. The left lane in both directions will be closed about 7 a.m. Thursday, continuing around-the-clock through late March as temporary crossovers through the median are constructed on I-79. The crossovers are necessary to allow crews to replace two I-79 bridges, one at a time, over Route 422 and Muddy Creek. About 25,000 vehicles use I-79 in this area each day, PennDOT stated. The $14 million project includes replacing both bridges, reconstruction of ramps and roads at the interchange, new overhead sign structures, a traffic monitoring camera and three digital message signs, as well as other improvements. Construction is scheduled for completion in fall 2014. The prime contractor for the project is the Trumbull Corp. of Pittsburgh.